Industrial centrifuges



Dec. 28, 1965 M Q COUPER ETAL 3,226,016

INDUSTRIAL CENTRIFUGES Filed July 9, 1962 5 Sheets-Sheet lWVWMAMHMMIWMMRMMMMNMM/VMA 1 AIXIFREQUEIJCY g n/ E j T E Z- FREQUEN' ["XFREQUENU z Z Zl* Z" l /9 E 3 5f 5b 55 34 /7 INVENTORS: Mervyn G. CouperLindsay Doubleday ATTORNEY Dec. 28, 1965 M COUPER ETAL 3,226,016 yINDUSTRIAL CENTRIFUGES Filed July 9, 1962 3 Sheets-Sheet 2.

INVENTORS: Mervyn G. Cou er Lindsay Doub eday ATTORNEY Dec. 28, 1965 MCOUPE-R ETAL 3,226,016

INDUSTRIAL CENTRIFUGES Filed July 9, 1962 3 Sheets-Sheet 5 L o n 60 5%Il M i" I 9 l/ l 25 l all 29 28 E-- 0f-: E B ACTlVE cb--o-Elo-*JowoINVENTORS:

L m m Mervyn G. Couper Lindsay Doubleday K T i@ R B B ml y TTORNEY )lUnited States Patent O 3,226,016 INDUSTRIAL CENTREUGES Merwu GeorgeCouper, Blackburn, and Lindsay Doubleday, West Footscray, Victoria,Australia, assignors to Monsanto Chemicals (Australia) Limited, WestFootscray, Victoria, Australia, acompany of Victoria Filed July 9, 1962,Ser. No. 208,197 19 Claims. (Cl. 233-23) This invention relates toindustrial centrifuges and provides means for effectively arrestingrotation of the centrifuge basket when so-ealled out-of-balancevibration or centrifuge basket imbalance-of-rotation frequency ofvibration occurs in the course of loading the centrifuge basket with aslurry of solids. More particularly. the invention relates tocentrifuges known as industrial suspended-basket type or batchcentrifuges, utilized mainly in the chemical industry for the recoveryof solids from aqueous slurries.

Conventional basket or batch centrifuges are invariably mounted with theaxis of the centrifuge basket disposed in the vertical plane, and,because of the possibility of uneven loading of the machine, the basketis normally supported by bearings, either above or below the basket, ina frame, so that a certain degree of flexibility in loading of thebasket is provided. Centrifuges with the support-bearing above thebasket are usually called either suspended or overhung type centrifuges,and it is to this type of centrifuge, that is to say, industrialsuspended-basket type centrifuges, that the present invention applies inparticular. Centrifuges of this particular type are constructed in sucha way as to remain balanced when they are loaded unevenly with solids.The centrifuge basket is supported by an overhung bearing mounted inrubber to provide flexibility, the basket being free to oscillate aboutthe support bearing, which is a fulcrum. The amount of oscillation isgoverned by the amount of flexibility in the rubber mounting of thesupport bearing, the basket rotating about its centre of gravity.

In the operation of centrifuges, particularly the suspended-basket type,vibrations can occur when the centrifuge basket is being loaded with aslurry of solids. These vibrations are of two kinds. The first is whenthere is an uneven loading of the slurry of solids, in this case thesolids in the slurry distributing unevenly around the centrifuge basketwith the result that the centrifuge rotates about the centre of gravityof the mass of the centrifuge basket and solids. With this kind ofvibration, the frequency corresponds to the centrifuge basket speed ofrotation The amplitude of vibration will depend on the distance theoriginal centre of gravity has been displaced. The displacement of thecentre of gravity depends on the mass of solids loaded unevenly. Withthis type of vibration the amplitude of vibration is constant, and thecentrifuge remains stable and balanced. This is shown in FIG. 1 of theaccompanying drawings, which graphically illustrates vibration amplitudeY and vibration frequency X as being constant, the frequency X being thenatural frequency of vibration of the centrifuge basket andcorresponding to the speed of rotation, said natural frequency beingmeasured by manually displacing the centrifuge basket sideways, allowingthe basket to oscillate freely, and measuring the frequency ofoscillation The second kind of vibration, which is essentially one ofincreasing intensity of amplitude, usually occurs when the centrifuge isbeing initially charged with a slurry or during Washing processes whenliquids are being charged on top of a layer of solid particles onso-called cake They only occur when the slurries or liquids are chargedtoo quickly or in long bursts. The liquids do not filter out quickly anda layer of liquid is formed on top of the cake. This vibration is asecondary vibration and is shown in FIG. 2 of the accompanying drawings,which graphically illustrates the increase in amplitude of vibrationamplitude Y, a vibration frequency Z being superimposed on vibrationfrequency X. The amplitude of vibration is of increasing intensity andviolent centrifuge basket imbalance-of-rotation occurs. The suppositionis that the second kind of 'vibration is caused by the layer of liquidon top of the cake in the basket slipping and rotating around the basketat a speed slower than the speed of the basket, a series of Waves beingset up which rotate around the basket thereby causing the centre ofgravity to shift continually. The centrifuge basket is assumed toendeavour to rotate around the shifting centre of gravity and becomesunbalanced. From measurements made with a suspended-basket typecentrifuge, the frequency of the second kind of vibration was found tocorrespond to the natural frequency of the centrifuge basket and isencountered when the centrifuge basket is rotating up to or down frommaximum speed and when the centrifuge basket is in imbalance.

In order effectively to arrest said second kind of vibration, thecentrifuge drive motor must be de-energized and the centrifuge brakeapplied within a second or two of the imbalance-of-rotation vibrationsoccurring. In examining the problem of effectively arresting suchimbalance-of-rotation vibrations it was found by us that vibrationalamplitude was ineffective as a sensing medium because the amplitude atwhich a sensing device based thereon might operate was too great toensue effective arresting of the imbalance-of-rotation vibrations. Anamplitude sensing device set to operate at small enough amplitudes toensue effective control was found to operate when the centrifugeencountered the first occurrence of vibration.

We have now developed centrifuge basket imbalanceof-rotation arrestingor control means for industrial centrifuges, in which a resonant reeddevice resonant-responsive to centrifuge basket imbalance-of-rotationfrequency of vibration is arranged to de-energize the centrifugeelectric-drive motor and actuate the centrifuge basket braking mechanismwhen imbalance-of-rotation vibration is encountered and bring thecentrifuge basket to rest. The arangement conventiently comprises a nantreed and weight device tuned to the natural frequency quency of thecentrifuge basket and resonant-responsive to centrifuge basketimbalance-of-rotation vibration, said reed and weight device beinglocated to strike and actuate an electrical microswitch in thecentrifuge drive motor electrical circuit for de-energizing said motorand actuating the centrifuge basket brake mechanism. When the frequencyof vibration of the centrifuge basket corresponding to the naturalfrequency of vibration of said resonant reed and weight device isencountered in reaching the maximum speed or rotation of said basket,causing incidental resonance of the resonant reed and weight device andwhich would result in accidental de-cnergization of the drive motor andactuation of the centrifuge basket brake mechanism, an electrical switchis included in said circuit to restrain de-energization of said motorand allow the centrifuge basket to reach maximum speed. By theapplication of this invention, centrifuge basket imbalance-of-rotationcan be arrested automatically before it becomes dangerous,

Thus, in accordance with this invention, centrifuge basketimbalance-of-rotation arresting means is provided in an industrialcentrifuge equipped with an electrical drive motor and a brake for thecentrifuge basket, said arresting means comprising a resonant reeddevice resonantresponsive to centrifuge basket imbalance-ofrotationfrequency of vibration, means for de-energizing said electrical drivemotor and actuated when said resonant reed device resonates responsiveto said centrifuge basket imbalance-of-rotation frequency of vibration,means for actuating said centrifuge basket brake when said resonant reeddevice resonates responsive to said centrifuge basketimbalance-of-rotation frequency of vibration, and means restrainingde-energization of said electrical drive motor and actuation of saidcentrifuge basket brake when the frequency of vibration of thecentrifuge basket corresponding to the natural frequency of vibration ofsaid resonant reed device is encountered in reaching the maximum speedof rotation of said centrifuge basket.

More particularly, the invention provides centrifuge basketimbalance-of-rotation arresting means in an industrial suspended-baskettype centrifuge equipped with an electrical drive motor and a brake forthe centrifuge basket, said arresting means comprising a resonant reedand weight device resonant-responsive to centrifuge basketimbalance-of-rotation frequency of vibration, drive motor de-energizingmeans comprising a primary electrical switch in said drive motorelectrical circuit and switch actuating mechanism located to be struckby said resonant reed and weight device when said resonant reed andweight device resonates responsive to said centrifuge basketimbalance-of-rotation frequency of vibration, a secondary electricalswitch in said electrical circuit for actuating mechanism connected toapply said centrifuge basket brake when said drive motor isde-energized, and an electrical short-circuiting switch in saidelectrical circuit connected to short-circuit said primary electricalswitch means and maintain operative said drive motor until thecentrifuge basket passes a speed of rotation corresponding to thenatural frequency of vibration of said resonant reed and weight devicein reaching the maximum speed of rotation of said centrifuge basket.

Said drive motor de-energizing means preferably comprises a switchactuating member located to be struck by said resonant reed and weightdevice when said resonant reed and weight device resonates responsive tosaid centrifuge basket imbalance-of-rotation frequency of vibration, anda primary electrical switch in said drive motor electrical circuitconnected for actuation by said switch actuating member; whilst thecentrifuge basket brake actuating means preferably comprises aspring-loaded ram urging operation of the brake and fluid pressureconstrained from said operation, a solenoid valve operative to admitfluid under pressure from a source of supply to said ram or vent fluidfrom said ram, and a secondary electrical switch in said drive motorelectrical circuit connected to actuate said solenoid valve and ventfluid from said ram When said drive motor is de-energized. In thisembodiment of the invention, a fluid-pressure sensitive electricalswitch is advantageously interposed between said fluid pressure sourceof supply and said solenoid valve and connected in said drive motorelectrical circuit for short-circuiting said drive motor when said ram`has less than a predetermined fluid pressure operative to constrain saidcentrifuge basket brake actuating means. The provision of saidfluid-pressure sensitive electrical switch is a safety measure to ensurethat the drive motor is automatically de-energized and not damaged bycontinued operation and over-heating in the event that the centrifugebasket brake mechanism is accidentally actuated due to a pressurefailure in the fluid-pressure source of supply.

The resonant reed and weight device are conveniently mounted on thecentrifuge so as to be suspended axially above the basket suspensionshaft of a suspended-basket type centrifuge, whilst the spring-loadedram, the solenoid valve, and the secondary electrical switch areconveniently mounted on the centrifuge frame, the springloaded ram beingsuitably connected to the centrifuge brake mechanism. For this purpose,the assembly of the resonant reed and weight device, the switchactuating member located to be struck by said resonant reed and Weightdevice, and the primary electrical switch may be embodied in a housingfixed to a stub shaft mounted to freewheel stationarily on the upper endof the basket suspension shaft with the resonant reed and weight devicesuspended axially above the basket suspension shaft.

In order, however, that the invention may be fully understood, furtherreference will be made to the accompanying drawings, which illustratesaid practical embodiment of the invention, and in which drawings:

FIG. 3 is a front elevational view partially broken away and in sectionof a suspended-basket type centrifuge equipped with arresting meansconstructed in accordance with the present invention, for the centrifugebasket when imbalance-of-rotation vibration occurs;

FIG. 4 is an enlarged front elevational view partially broken away andin section of the housing and motor deenergizing means assembly seen inFIG. 3;

FIG. 5 is a cross-sectional plan view taken at lines 5 5 of FIG. 3;

FIG. 6 is a cross-sectional plan View taken at lines 6-6 of FIG. 3; and

FIG. 7 is a diagrammatic view of the centrifuge drive motor electricalcircuit and including the electrical switches specified above.

Referring to FIGS. 3 to 6 of the drawings, the suspended-basket typecentrifuge illustrated therein is shown to consist of a frame formed bya pair of vertical channel members 1 joined by .an overhead beam section2, a centrifuge-basket casing 3 extending between said vertical channelmembers 1. Centrifuge basket 4 is suspended in said casing 3 by means ofbasket-suspension shaft 5 supported in bearing 6 located in overheadbeam 2, the bearing 6 having a rubber liner 7 to provide ilexibility inthe 4suspension of centrifuge basket 4. Basketsuspension shaft 5 has adrive pulley 8 and a brake drum or pulley 9. Belt driving 10 connectsdrive pulley r8 with centrifuge drive motor 11 mounted on the centrifugeframe 1 by bracket 12. Basket suspension shaft 5 also has a coupling 13fixed to the upped end of said shaft, a stub shaft 14 being tted tofreewheel stationarily in the coupling. Said coupling 13 may also have adog clutch 13A, the dog clutch being operative only when a centrifugeplow (not shown) is employed, in which case a plow drive pulley (notshown) is xed to frustum portion 14A of stub shaft 14 in lieu of theassembly shown fixed to said frustum, in order to rotate the basketsuspension shaft 5 in a direction counterwise to the rotation directionof drive pulley 8, in the plowing the basket load for discharge from thebasket. Basket brake mechanism 15 is suitably mounted on overhead beam 2to co-act with brake drum 9.

Fixed to frustum 14A of stub shaft 14, in accordance with the invention,is a housing structure 16 which advantageously is restrained by chain 17attached to the housing structure and to overhead beam 2, from gainingrotation momentum through stub shaft 1,4 freewheeling in coupling 13.Suspended from the top of the housing structure 16 and depending axiallyabove the basket suspension shaft 5 is a spring steel resonant reed 18having a weight 19 attached to the outer end of said reed. The mass ofthe reed and weight device is relatively small so that it respondsquickly to centrifuge basket imbalance-of-rotation vibration and reachesamplitudes of say two inches in about 1.50 seconds, the Weight 19'beingchosen so that the reed and weight is tuned for resonance in Sympathywith the natural frequency of vibration of the centrifuge basket 4.Limitstop 20 protrudes from one side of the housing structure 16 torestrict the amplitude of oscillation of the reed and Weight device, inorder to lessen metal-fatitgue rate of the reed. Extending from theother side of said housing structure 16 and located to be struck by saidreed and weight device when resonating as indicated, is a switchactuating arm 21 of primary electrical switch or microswitch 22, saidmicroswitch 22 being included in the centrifuge drive motor electricalcircuit for deenergization of said motor. Switch actuating arm 21 is sodisposed in the housing structure and set that the reed and weightdevice is arranged to strike said switch arm within approximately 1.00seconds of centrifuge basket imbalance-of-rotation vibration occurring.

Brake drum 9 is engaged by basket friction-brake band 23 actuated by thebasket brake mechanism 15. Said brake mechanism consists of aduid-pressure ram cylinder 24 pivotally mounted on supporting bracket 25attached to the overhead beam 2 of the centrifuge frame and having acompression spring 26 reacting against ram plunger 27, the outer end ofsaid ram plunger being pivotally connected to one end of lever 28 whichis attached at the other end to pivot 29 mounted on a transverse member30 of the centrifuge frame overhead beam 2. The ends of friction-brakeband 23 are also attached to lever 2S and pivot 29, outward movement ofram plunger 27 causing said friction-brake band 23 to be tightened aboutbrake drum 9 an exert a braking action on brake drum 9. Compressionspring 26 urges braking operation of friction-brake band 23 in reactingagainst ram plunger 27 but is constrained from such operation byfluid-pressure admitted to ram cylinder 24 by duid-pressure line 31serviced from any suitable fluid pressure source of supply (not shown).A supply of air pressure is adequate for the purpose. Solenoid valve 32is located in Huid-pressure line 31 to admit the supply of uid pressureto ram cylinder 24 in constraining the compression spring 26 fromoperation of the brake, or, to vent fluid from said ram cylinder so-that said compression spring 26 may effect operation of the brake. Thesolenoid valve 32 has a secondary electrical switch (not shown in FIGS.3 to 6 but shown in FIG. 7) in the centrifuge drive motor electricalcircuit for actuation to vent fluid pressure from ram cylinder 24 whensaid drive motor is cle-energized. Also imposed in fluidpressure line 31and located between said solenoid valve 32 and the uid pressure sourceof supply is fluidpressure sensitive switch 33, which is connected inthe centrifuge drive motor electrical circuit for sh0rtcircuitingenergization of said drive motor when said ram cylinder 24 has less thana predetermined fluid pressure which is operative to constrain saidcompression spring 26 from :actuating the brake.

Centrifuge drive motor 11 is provided with a conventional type ofc-entrifugally operated electrical shortcircuiting switch means 34connected in the electrical circuit of said motor to short-circuit.primary electrical switch or microswitch 22 and maintain said motoroperative when the centrifuge basket 4 passes a speed of rotationcausing vibrations corresponding to the natural frequency of vibrationof the reed and weight device, in reaching the maximum speed of rotationof said basket. Switch means 34 is driven by belt-drive 35 from a pulley36 on centrifuge clutch 37 of drive motor 11. Housing structure 16 maybe enclosed by a woven metal gauze to form a cage for the protection ofthe resonant reed and weight device and incidentally prevent loss of theweight in the event that the spring steel of the resonant reed were tobreak due to metal fatigue.

FIG. 7 of the drawings shows an electrical circuit diagram suitable forthe apparatus of the invention. In the circuit diagram, B represents thefluid-pressure sensitive switch 33 introduced into the circuit toprevent the centrifuge from operation until and unless there is apredetermined fluid or air pressure to operate the brake mechanism. The`switch 33 is normally closed if the fluid pressure is suicient toconstrain the compression spring 26 from actuating the brake. The switch33 will open only if the fluid or air pressure in the ram cylinder 24 isless than that predetermined for the purpose. D represents theelectrical short-circuiting switch means 34 and operates to shortcircuit microswitch 22 and prevent microswitch 22 from denergizing thecentrifuge basket when accelerating through the speed exceeding thatcorersponding to the reed and weight device natural frequency ofvibration. The short-circuiting switch D is normally closed and will notopen until the centrifuge basket exceeds such speed. E represents themicroswitch 22, which is normally closed and opens only when struck bythe reed and weight device. F represents the centrifuge basket drivemotor stop-start station switch. G represents the centrifuge basketdrive `motor relay supplying three phase current to said motor, whenclosed by pressing the start button of the stopstart station switch. Hrepresents an auxiliary contactor normally open and coupled to the drivemotor contactors for closing when the drive motor contactors are closedby pressing the start button. The closing of the auxiliary contactor Hwill energize the solenoid valve 32. J represents a fuse. K representsthe solenoid valve 32 which opens when energized, admitting fluid or airpressure to` ram cylinder 24 and constraining the brake from operationor releasing the brake after operation. The solenoid valve is designedto vent the ram cylinder 24 to apply the brake when de-energized, thearrangement being such that when the start button is pressed thesolenoid valve is energized thus releasing the brake and allowing thecentrifuge to rotate. When the microswitch 22 is actuated or the stopbutton is pressed the solenoid valve is de-energized thus venting theram cylinder 24 and causing application of the brake. L represents ahold-in contactor which holds the three phase current and auxiliarycontactor after the start button has been reclased, when the centrifugebasket is in the starting stage. M is a thermal overload to protect thecentrifuge drive motor from overheating by so-called two-phasing of thethree phase current supply.

In operation, when the start button of the stop-start station is pressedto start the centrifuge drive motor 11, current Hows from the activelead of the circuit through switch B (which is closed due to suicientair pressure in ram cylinder 24), through speed switch D (closed due tothe centrifuge basket being stationary), through stopstart station,through relay G, through thermal overload swich M to the neutral lead.When relay G is energized it closes contactors L and H and the threephase drivemotor contactors, which start the centrifuge drive motor.With contactor H closed, the current flows from active lead through fuseI, then energizes solenoid valve K which releases the brake, allowingthe centrifuge basket to rotate. When the start button is released,contactor L being closed causes the current to by-pass the start buttonand keep relay G energized thus maintaining the circuit active. As thecentrifuge basket speed of rotation passes the critical spe-edcorresponding to the natural frequency of vibration of the reed andweight device, switch D opens, making microswitch E active. In the eventof centrifuge basket imbalance-of-rotation vibration occurring,microswitch E is opened by being struck by the reed and Weight devicethereby breaking the circuit to relay G. With relay G de-energized,contactors L and H open, causing solenoid valve Kto be de-energized,whereupon the three phase current is cut from centrifuge drive motor andthe brake is applied. When the stop button is pressed the circuit torelay G is broken, the centrifuge motor is de-energized and the brake isapplied as in the case of centrifuge basket imbalance-of rotationvibration.

The embodiments of the invention in which an exclusive property orprivilege is claimed are defined as follows:

1. An imbalance-of-rotation arresting means for use with an industrialcentrifuge equipped with a rotatably mounted centrifuge basket, anelectrical drive motor associated with said centrifuge for driving saidcentrifuge basket, and a brake for retarding the rotational movement ofthe centrifuge basket; said imbalance-of-rotation arresting meanscomprising a resonant reed device operatively associated with saidcentrifuge and being resonantresponsive to centrifuge basketimbalance-of-rotation frequency of vibration, said resonant reed devicebeing substantially coaxially aligned with the center of rotation ofsaid centrifuge basket, means operatively associated with said resonantreed device and said electrical drive motor for de-energizing saidelectrical drive motor, said last named means being actuated when saidresonant reed device resonates responsive to said centrifuge basketimbalance-of-rotation frequency of Vibration, means operativelyassociated with said resonant reed device and said brake for actuatingsaid centrifuge basket brake when said resonant reed device resonatesresponsive to said centrifuge basket imbalance-of-rotation frequency ofvibration, and means operatively connected to each of said last namedmeans for restraining de-energization of said electrical drive motor andrestraining actuation of said centrifuge basket brake when the frequencyof vibration 4of the centrifuge basket corresponding to the naturalfrequency of vibration of said resonant reed device is encountered inreaching the maximum speed of rotation of said centrifuge basket.

2. An imbalance-of-rotation arresting means for use with an industrialsuspended-basket type centrifuge equipped with a suspended centrifugebasket, an electrical drive motor associated with said centrifuge fordriving said centrifuge basket, and a brake for retarding the rotationalmovement of the centrifuge basket; said imbalanceof-rotation arrestingmeans comprising a resonant reed and weight device operativelyassociated with said centifuge and being resonant-responsive tocentrifuge basket imbalance-of-rotation frequency of vibration, saidresonant reed and weight device being substantially coaxially alignedwith the center of rotation of said centrifuge basket, means operativelyconnected to said electrical drive motor and being located to be struckby said resonont reed and weight device and de-energize said electricaldrive motor when said resonant reed and weight device resonateresponsive to said centrifuge basket im- '.balance-of-rotation frequencyof vibration, means operatively associated with said resonant reed andweight de- ,vice and said brake for actuating said centrifuge basketbrake when said electrical drive motor is de-energized, and meansoperatively connected to each of said last named means for restrainingde-energization of said electrical drive motor and restraining actuationof said centrifuge basket brake when the frequency of vibration of thecentrifuge basket corresponding to the natural frequency of vibration ofsaid resonant reed and weight device is encountered in reaching themaximum speed of rotation of said centrifuge basket.

3. An imbalance-of-rotation arresting means for use with an industrialsuspended-basket type centrifuge equipped with a suspended centrifugebasket, an electrical drive motor associated with said centrifuge fordriving said centrifuge basket, and a brake for retarding the rotationalmovement of the centrifuge basket; said imbalanceof-rotation arrestingmeans comprising a resonant reed and weight device operativelyassociated with said centrifuge and being resonant-responsive tocentrifuge basket imbalance-of-rotation frequency of vibration, saidresonant reed and weight device being substantially coaxially alignedwith the center of rotation of said centrifuge basket, drive motorde-energizing means operatively -connected to said drive motor andcomprising a primary electrical switch and switch actuating mechanism,means for locating said switch actuating mechanism to be struck by saidresonant reed and weight device when said resonant reed and weightdevice resonates responsive to said centrifuge basketimbalance-of-rotation frequency of vibration, a -secondary electricalswitch operatively associated with said primary electrical switch andbrake for actuating said centrifuge basket brake when said drive motoris de-energized, and an electrical short-circuting switch operativelyconnected to short-circuit said primary electrical switch and maintainenergization of said drive motor until the centrifuge basket passes aspeed of rotation corresponding to the natural frequency of vibration ofsaid resonant reed and weight device in reaching the maximum speed ofrotation of said centrifuge basket.

4. An imbalance-of-rotation arresting means for use with an industrialsuspended-basket type centrifuge equipped with a suspended centrifugebasket, an electrical drive motor associated with said centrifuge fordriving said centrifuge basket, and a brake for retarding the rotationalmovement of the centrifuge basket; said imbalance-of-rotation arrestingmeans comprising a resonant r'eed and weight device operativelyassociated with said centrifuge and being resonant-responsive tocentrifuge basket imbalance-of-rotation frequency of vibration drivemotor, said resonant reed device being substantially coaxially alignedwith the center of rotation of said centrifuge basket, de-energizingmeans comprising a switch actuating member, means for locating saidswitch actuating member to be struck by said resonant reed and weightdevice when said resonant r'eed and weight device resonates responsiveto said centrifuge basket imbalance-of-rotation frequency of vibration,said motor de-energizing means also comprising a primary electricalswitch operatively connected to said electrical drive motor and beingadapted for actuation by said switch actuating member, centrifuge basketbrake actuating means comprising a spring-loaded ram urging applicationof said brake to restrain movement of said centrifuge basket, means forapplying fluidpressure to said ram to constrain said centrifuge basketbrake from operation, a solenoid valve operatively interposed betweensaid ram and means for applying fluid-pressure and being adapted tooptionally admit fluid under pressure to said ram or vent uid from saidram, a secondary electrical -switch operatively associated with said ramand being operatively connected to actuate said soienoid valve and ventfluid from said ram when said drive motor is de-energized, and anelectrical short-circuiting switch operatively connected toshort-circuit said primary electrical switch and maintain energizationof said drive motor until the centrifuge basket passes a speed ofrotation corresponding to the natural frequency of vibration of saidresonant reed and weight device in reaching the maximum speed ofrotation of said centrifuge basket.

5. Apparatus as in claim 4, wherein a duid-pressure sensitive electricalswitch is interposed between said means for applying duid-pressure andsaid solenoid valve for short-circuiting said drive motor when said ramhas less than a predetermined uid pressure necessary to cosntrain saidcentrifuge basket brake actuating means.

6. An industrial suspended-basket type centrifuge comprising framemeans, a basket suspension shaft operatively mounted on said framemeans, an electrical drive motor operatively mounted on said framemeans, a suspended centrifuge basket operatively mounted on saidsuspension shaft for rotative movement with respect to said frame means,a brake mechanism operatively mounted on said frame means for -retardingrotational movement of said centrifuge basket, a brake pulley mounted onthe suspension shaft and being in cooperative relationship with saidbrake mechanism for restraining movement of said centrifuge basket, saidcentrifuge having centrifuge basket imbalance-of-rotation arrestingmeans comprising a resonant reed and weight device operatively mountedon said frame means and being resonant-responsive to centrifuge basketimbalance-of-rotation frequency of vibration, said resonant reed andweight device being substantially coaxially aligned with said suspensionshaft, a switch actuating member operatively mounted on said framemeans, means for locating said switch actuating member to be struck bysaid resonant reed and weight device when said resonant reed and weightdevice resonates responsive to l saidcentrifuge basketimbalance-of-rotation frequency of vibration, a primary electricalswitch Iop'eratively connected to said electrical drive motor and beingadapted for actuation by said switch actuating member, said resonantreed and weight device being suspended axially above the basketsuspension shaft in proximate alignment with said switch actuatingmember, a spring-loaded ram mounted on the centrifuge frame means andbeing connected to the brake mechanism and urging application of thebrake mechanism to restrain movement lof said centrifuge basket, meansfor applying fluid pressure to said ram to constrain said centrifugebasket brake from operation, a solenoid valve operatively interposedbetween said ram and means for applying fluid-pressure and being adaptedto optionally admit fluid under pressure to said ram or vent fluid fromsaid ram, a secondary electrical switch operatively associated with saidram and being operatively connected t actuate said solenoid valve andvent fluid from said ram when said drive motor is de-energized, and anelectrical short-circuiting switch operatively connected toshort-circuit .said primary electrical switch and maintain energizationof said drive motor until the centrifuge basket passes a speed ofrotation corresponding to the natural frequency of vibration of saidresonant reed and weight device in reaching the maximum speed ofrotation of said centrifuge basket.

7. Apparatus as in claim 6, wherein a fluid-pressure sensitiveelectrical switch is interposed between said means for applyingfluid-pressure and said solenoid valve for short-circuiting said drivemotor when said ram has less than a predetermined fluid pressurenecessary to constrain said centrifuge basket brake actuating means.

8. An industrial suspended-basket type centrifuge comprising framemeans, a basket suspension shaft operatively mounted on said framemeans, an electrical drive motor operatively mounted on said framemeans, a suspended centrifuge basket operatively mounted on saidsuspension shaft for rotative movement with respect to said frame means,a brake mechanism Ioperatively mounted on said frame means for retardingrotational movement of said centrifuge basket, a brake pulley mounted onthe suspension shaft and being in cooperative relationship with saidbrake mechanism for restraining movement of said centrifuge basket, astub shaft operatively m-ounted on the upper end of the suspension shaftto freewheel stationarily thereon, a housing fixedly mounted on saidstub shaft, said centrifuge having centrifuge basketimbalance-ofrotation arresting means comprising the assembly of aresonant reed and weight device operatively mounted on said. stub shaftand being resonant-responsive to centrifuge basket imbalance-of-rotationfrequency of vibration,

said resonant reed and weight device being substantially coaxiallyaligned with said suspension shaft, a switch actuating memberoperatively mounted on said housing, means for locating said switchactuating member to be struck by said resonant reed and weight devicewhen said resonant reed and weight device resonates responsive to saidcentrifuge basket imbalance-of-rotation frequency of vibration, aprimary electrical switch operatively connected to said electrical drivemotor and being adapted for actuation by said switch. actuating member,said resonant reed and weight device being suspended axially above thebasket suspension shaft in proximate alignment with said switchactuating member, a spring-loaded ram mounted on the centrifuge framemeans and being connected to the brake mechanism and urging applicationof the brake mechanism to restrain movement of said centrifuge basket,means for applying fluid pressure to said ram to constrain saidcentrifuge basket brake from operation, a solenoid Valve operativelyinterposed between said ram and means for applying fluid pressure andbeing adapted to optionally admit fluid under pressure to said ram orvent fluid from said ram, a secondary electrical switch operativelyassociated with -said ram and being operatively connected to a-ctuatesaid solenoid valve and vent fluid from said ram when said drive motoris deenergized, and an electrical short-circuiting switch operativelyconnected to short-circuit said primary electrical switch and maintainenergization of said drive motor until the centrifuge basket passes aspeed of rotation corresponding to the natural frequency of vibration ofsaid resonant reed and weight device in reaching the maximum speed oflrotation of said centrifuge basket.

9. Apparatus as in claim 8, wherein a fluid-pressure sensitiveelectrical switch is interposed between said means for applyingfluid-pressure and said solenoid valve for short-circuiting said drivemotor when said ram has less than a predetermined fluid pressurenecessary to constrain said centrifuge basket brake actuating means.

10. An industrial suspended-basket type centrifuge comprising framemeans, a basket suspension shaft operatively mounted on -said framemeans, an electrical drive motor operatively mounted on said framemeans, a suspended centrifuge basket operatively mounted on saidsuspension shaft for rotative movement with respect to said frame means,a brake mechanism operatively mounted on said frame means for retardingrotational movement of said centrifuge basket, a brake pulley mounted onthe suspension shaft and being in cooperative relationship with saidbrake mechanism for restraining movement of said centrifuge basket, astub shaft operatively mounted on the upper end of the suspension shaftto freewheel stationarily thereon, a housing fixedly mounted on saidstub shaft, -said centrifuge having centrifuge basketimbalance-of-rotation arresting means comprising the assembly of aresonant reed and weight device operatively mounted on said stub shaftand being resonant-responsive to centrifuge basket imbalance-of-rotationfrequency of vibration, said resonant reed and weight device beingsubstantially coaxially aligned with said suspension shaft, a switchactuating member operatively mounted on said housing, means for locatingsaid switch actuating member to be struck by said resonant reed andweight device when said reso-- nant reed and weight device resonatesresponsive to said centrifuge basket imbalance-of-rotation frequency ofvibration, a primary electrical switch operatively connected to saidelectrical drive motor and being adapted for actuation by said switchactuating member, said resonant reed and weight device being suspendedaxially above the basket suspension shaft in proximate alignment withsaid switch actuating member, a fluid pressure ram having a cylinderpivotally mounted on the centrifuge frame and having a ram plungershiftably disposed within said cylinder, a lever pivotally mounted onthe centrifuge frame and being attached at one end to the free end ofthe ram plunger, a friction-brake band operatively disposed about saidsuspension shaft for retarding rotational movement of said suspensionshaft when said band is pulled to a taut condition, said friction-brakeband being connected to the other end of said lever, a compressionspring located within the ram cylinder to urge operation of thefrictionbrake band, a source of fluid under pressure, a fluid pressureline from said source -of fluid connected to said ram cylinder toconstrain said braking operation, a solenoid Valve in said fluidpressure line and being adapted to optionally admit fluid to said ram orvent fluid from said ram, a secondary electrical switch operativelyassociated with said ram and being operatively connected t-o actuatesaid solenoid valve and vent fluid from said ram when said drive motoris de-energized, a fluid-pressure sensitive electrical switch interposedin said fluid pressure line between said source of fluid and saidsolenoid valve and being operatively connected to said drive motor forshort-circuiting said drive motor when said ram has less than apredetermined fluid pressure necessary to constrain said ram fromcausing application of the friction-brake band, and an electricalshort-circuiting switch operatively connected to short-circuit saidprimary electrical switch and maintain energization of said drive motoruntil the centrifuge basket passe-s a speed of rotation corresponding tothe natural frequency of vibration of said resonant reed and Weightdevice in reaching the maximum speed of rotation of said centrifugebasket.

11. An imbalance-of-rotation arresting means for use with a gyratoryapparatus equipped With a rotatably mounted gyratory member, a drivemeans associated with said gyratory apparatus for driving said gyratorymember, and a brake for retarding the rotational m-ovement of th'egyratory member, said imbalance-of-rotation arresting means comprising aresonant reed device operatively associated With said gyratory apparatusand being resonant-responsive to the gyratory memberimbalanceof-rotation frequency of vibration, said resonant reed devicebeing substantially coaxially aligned With the center Iof rotation ofsaid gyratory member, de-energization means operatively associated withsaid resonant reed dcvice and said drive m'eans for de-energizing -saiddrive means, said de-energization means being actuated When saidresonant reed device resonates responsive to said gyratory memberimbalance-of-rotation frequency o-f vibration, and means operativelyassociated with said r'esonant reed device and said brake for actuatingsaid brake when said resonant reed device resonates responsive to saidgyratory member imbalance-of-rotation frequency of vibration.

12. An imbalance-of-rotation arresting means for use with an industrialcentrifuge equipped with a rotatably mounted centrifuge basket, anelectrical drive motor associated with said centrifuge for driving saidcentrifuge basket, and a brake for retarding the rotational movement ofthe centrifuge basket; said imbalance-of-rotation arresting meanscomprising a resonant reed device operatively associated with saidcentrifuge and being resonantresponsive to centrifuge basketimbalance-of-rotation frequency of vibration, said resonant reed devicebeing substantially coaXially aligned with the center of rotation ofsaid centrifuge basket, means operatively associated with said resonantreed device and said electrical drive motor for deenergizing saidelectrical drive motor, said last named means being actuated when saidresonant reed device resonates responsive to said centrifuge basketimbalance-of-rotation frequency .of vibration, and means operativelyassociated with said resonant reed device and said brake for actuatingsaid centrifuge basket brake when said resonant reed device resonatesresponsive to said centrifuge basket imbalance-of-rotation frequency ofvibration,

13. An imbalance-of-rotation arresting means for use With a gyratoryapparatus equipped with a rotatably mounted gyratory member, drive meansassociated with said gyratory apparatus for driving said gyratory memberand a brake for retarding the rotational movement of the gyratorymember; said imbalance-of-rotation arresting means comprising a resonantreed device operatively associated with said gyratory apparatus andbeing resonant-responsive to the gyratory member imbalance-of-rotationfrequency of vibration, said resonant reed device being substantiallycoaxially aligned with the center of rotation of said ygyratory member,de-energization means operatively associated with said resonant reeddevice and said drive means 'for de-energizing said drive means, saidde-energization means being actuated when said resonant reed deviceresonates responsive to said gyratory member imbalance-of-rotationfrequency of vibration, means operatively associated with said resonantreed and said brake for actuating said brake when said resonant reeddevice resonates responsive to said gyratory memberimbalance-of-rotation frequency of vibration, and means operativelyconnected to said last named means and said de-energization means lforrestraining de-energization -of said drive means and restrainingactuation of said brake when the frequency of vibration of the gyratorymember corresponding to the natural frequency of vibration of saidresonant reed device is encountered in reaching the maximum speed ofrotation vof said gyratory member.

14. An imbalance-of-rotation arresting means for use with a gyratoryapparatus equipped with a rotatably mounted gyratory member, drive meansassociated With said gyratory apparatus for driving said gyratorymember, and a brake for retarding the rotational movement of thegyratory member; said imbalance-of-rotation arresting means comprisingvibration sensing means operatively associated With said gyratoryapparatus and being responsive to the gyratory memberimbalance-of-rotation frequency of vibration, said vibration sensingmeans being substantially coaxially aligned with the center of rotationof said gyratory member, de-energization means operatively associatedwith said vibration sensing means and said drive means for de-energizingsaid drive means, said de-energization means being actuated when saidvibration sensing means detects a gyratory member imbalanceof-rotationfrequency of vibration, means operatively associated With said vibrationsensing means and said brake for actuating said brake When saidvibration sensing means detects said gyratory memberimbalance-of-rotation frequency of vibration, and means operativelyconnected to said last named means and said de-energization means forrestraining de-energization of said drive means and restrainingactuation of said brake when the frequency of vibration of the gyratorymember corresponding to the natural frequency of vibration of saidvibration sensing means is encountered in reaching the maximum speed ofrotation of said gyratory member.

l5. An imbalance-of-rotation arresting means for use With an industrialcentrifuge equipped with a rotatably mounted centrifuge basket, anelectrical drive motor associated with said centrifuge for driving saidcentrifuge basket, and a brake for retarding the rotational movement ofthe centrifuge basket; said imbalance-of-rotation arresting means`comprising vibration sensing means operatively associated with saidcentrifuge and being responsive to centrifuge basketimbalance-of-rotation frequency of vibration, said vibration sensingmeans being substantially coaxially aligned with the center of rotationof said centrifuge basket, de-energization means operatively associatedwith said vibration sensing means and said electrical drive motor forde-energizing said electrical drive motor, said de-energization meansbeing actuated when said vibration sensing means detects a centrifugebasket imbalance-ofrotation frequency of vibration, means operativelyassociated with said vibration sensing means and said brake foractuating said centrifuge basket brake when said vibration sensing meansdetects centrifuge basket imbalance-ofrotation frequency of vibration,and means operatively connected to each of said last named means forrestraining de-energization of said electrical drive motor andrestraining actuation of said centrifuge basket brake when the frequencyof vibration of the centrifuge basket corresponding to the naturalfrequency of vibration of said vibration sensing means is encountered inreaching the maximum speed of rotation of said centrifuge basket.

16. A gyratory apparatus comprising frame means, a gyratory member shaftoperatively mounted on said frame means, an electrical drive motoroperatively mounted on said frame means, a suspended gyratory memberoperatively mounted on said suspension shaft for rotative movement withrespect to said frame means, a brake mechanism operatively mounted onsaid frame means for retarding rotational movement of said gyratorymember, a brake pulley mounted on the suspension shaft and being incooperative relationship with said brake mechanism for restrainingmovement of said gyratory member, said gyratory apparatus havingimbalance-ofrotation arresting means comprising a resonant reed andweight device resonant-responsive to gyratory memberimbalance-of-rotation frequency of vibration, said resonant reed andweight device being substantially coaxially aligned With the gyratorymember shaft, a switch actuating member operatively mounted on saidframe means, means for locating said switch actuating member t-o bestruck by said resonant reed and weight device when said resonant redand Yweight device resonates responsive to said imbalance-of-rotationfrequency of vibration, a primary electrical switch operativelyconnected to said electrical drive motor and being adapted for actuationby said switch actuating member, said resonant reed and weight devicebeing suspended axially above the suspension shaft in proximatealignment with said switch actuating member, a spring-l-oaded rammounted on the frame means and being connected to the brake mechanismand urging application of the brake mechanism to restrain movement ofsaid gyratory member, means for applying fluid pressure to said ram toconstrain said centrifuge basket brake from operation, a solenoid valveoperatively interposed between said ram and means for applyingfluid-pressure and being adapted tooptionally admit fluid under pressureto said ram -or vent fluid from said ram, a secondary electrical switchoperatively associated with said ram and being operatively connected toactuate said solenoid valve and vent fluid from said ram when said drivemotor is de-energized, and an electrical short-circuiting switchoperatively connected to short-circuit said primary electrical switchand maintain energization of said drive motor until the gyratory memberpasses a speed of rotation corresponding to the natural frequency ofvibration of said resonant reed and weight device in reaching themaximum speed of rotation of said gyratory member.

17. An industrial suspended-basket type centrifuge comprising framemeans, a basket suspension shaft operatively mounted on said framemeans, an electrical drive motor operatively mounted on said framemeans, a suspended centrifuge basket operatively mounted on saidsuspension shaft for rotative movement with respect to said frame means,a brake mechanism operatively mounted on said frame means for retardingrotational movement of said centrifuge basket, a brake pulley mounted onthe suspension shaft and being in cooperative relationship with saidbrake mechanism for restraining movement of said centrifuge basket, saidcentrifuge having centrifuge basket imbalance-of-rotation arrestingmeans comprising vibration sensing means operatively mounted on saidframe means and being responsive to centrifuge basketimbalance-of-rotation frequency of vibration, said vibration sensingmeans being substantially coaxially aligned with said basket suspensionshaft, a switch actuating member operatively mounted on said framemeans, means for locating said switch actuating member to be struck bysaid vibration sensing means when said vibration sensing means detectscentrifuge basket imbalance-of-rotation frequency of vibration, aprimary electrical switch operatively connected to said electrical drivemotor and being adapted for actuation by said switch actuating member,said vibration sensing means being suspended axially above the basketsuspension shaft in proximate alignment with said switch actuatingmember, a spring-loaded ram mounted on the centrifuge frame means andbeing connected to the brake mechanism and urging application of thebrake mechanism to restrain movement of said centrifuge basket means forapplying fluid pressure to said ram to constrain said centrifuge basketbrake from operation, a solenoid valve operatively interposed betweensaid ram and means for applying fluid pressure and being adapted tooptionally admit fluid under pressure to said ram or vent fluid fromsaid ram, a secondary electrical switch operatively associated with saidram and being operatively connected to actuate said solenoid valve andvent fluid from said ram when said drive motor is deenergized, and anelectrical short-circuiting switch circuit operatively connected toshort-circuit said primary electrical switch and maintain energizationof said drive motor until the centrifuge basket passes a speed ofrotation corresponding to the natural frequency of vibration of saidvibration sensing means in reaching the maximum speed of rotation ofsaid centrifuge basket.

18. A gyratory apparatus comprising frame means, a gyratory membersuspension shaft operatively mounted on said frame means, an electricaldrive motor operatively mountd on said frame means, a suspended gyratorymember operatively mounted on said suspension shaft for rotativemovement with respect to said frame means, a brake mechanism operativelymounted on said frame means for retarding rotational movement of saidgyratory member, a brake pulley mounted on the suspension shaft andbeing in cooperative relationship with said brake mechanism forrestraining movement of said gyratory member, said gyratory apparatushaving imbalanoe-of-rotation arresting means comprising vibrationsensing means operatively mounted on said frame means and beingresponsive to gyratory member imbalance-of-rotation frequency ofvibration, said vibration sensing means being substantially coaxiallyaligned with said gyratory member suspension shaft, a switch actuatingmember operatively mounted on said frame means, means for locating saidswitch actuating member to be struck by said vibration sensing meanswhen said vibration sensing means detects imbalance-of-rota tionfrequency of vibration, a primary electrical switch operativelyconnected to said electrical drive motor and being adapted for actuationby said switch actuating member, said vibration sensing means beingsuspended axially above the suspension shaft in proximate alignment withsaid switch actuating member, a spring loaded ram mounted on the framemeans and being connected to the brake mechanism and urging applicationof the brake mechanism to restrain movement of said gyratory member,means for applying fluid pressure to said ram to constrain saidcentrifuge basket brake from operation, a solenoid valve operativelyinterposed between said ram and means for applying fluid pressure andbeing adapted to optionally admit fluid under pressure to said ram orvent fluid from said ram, a secondary electrical switch operativelyassociated with said ram and being operatively connected to actuate saidsolenoid valve and vent fluid from said ram when said drive motor isde-energized, and an electrical short-circuiting switch operativelyconnected to short-circuit said primary electrical switch and maintainenergization of said drive motor until the gyratory member passes aspeed of rotation corresponding to the natural frequency of vibration ofsaid vibration sensing means in reaching the maximum speed of rotationof said gyratory member.

19. An industrial suspended-basket type centrifuge comprising framemeans, a basket suspension shaft operatively mounted on said framemeans, an electrical drive motor operatively mounted on said framemeans, a suspended centrifuge basket operatively mounted on saidsuspension shaft for rotative movement with respect to said frame means,a brake mechanism operatively mounted on said frame means for retardingrotational movement of said centrifuge basket, a brake pulley mounted onthe suspension shaft and being in cooperative relationship with saidbrake mechanism for restraining movement of said centrifuge basket, saidcentrifuge having centrifuge basket imbalance-of-rotation arrestingmeans comprising a resonant reed and weight device operatively mountedon said frame means and being resonant-responsive to centrifuge basketimbalance-of-rotation frequency of vibration, said resonant reed andweight device being substantially coaxially aligned with said suspensionshaft, a switch actuating member operatively mounted on said framemeans, means for locating said switch actuating member to be struck bysaid resonant reed and weight device when said resonant reed and weightdevice resonates responsive to said centrifuge basketimbalance-of-rotation frequency of vibration, a primary electricalswitch operatively connected to said electrical drive motor and beingadapted for actuation by said switch actuating member, said resonantreed and weight device being suspended axially above the basketsuspension shaft in proximate alignment with said switch actuatingmember, a spring-loaded ram mounted on the centrifuge frame means andbeing connected to the brake mechanism and urging application ofthebrake mechanism to restrain movement of said centrifuge basket means forapplying fluid pressure to said ram to constrain said centrifuge basketbrake from operation, a solenoid valve operatively interposed betweensaid ram an dmeans for applying huid-pressure and being adapted tooptionally admit iluid under pressure to said ram or vent iiuid fromsaid ram, and a secondary electrical switch operatively associated withsaid ram and being operatively connected to actuate said solenoid valveand vent fluid from said ram when said drive motor is de-energized.

References Cited by the Examiner UNITED STATES PATENTS Johnson 210-368 XSmith etal 210-144 X Morrison 210-144 Keiper 210-144 X Huser et al210-368 X Adams et al.

Evans et al.

Worst 210-144 Blum 210-144 X Stelli 210-144 Starr et al 210-144 France.

M. CARY NELSON, Primary Examiner.

WILLIAM F. BURNETT, Examiner.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No 3,226,O16 December 2S 1965 Mervyn George Couper et al.

It is certified that error appears in the a'bove identified patent andthat said Letters Patent are hereby corrected as shown below:

Column l, line 69, for "on", second occurrence, read or H column 2 lines3l and 34 for "ensue" Y, each occurrence read ensure line 45, after"comprises a" insert resonant line 46, strike out "nant"; line 47,strike out "quency"; column 4, line 49, strike out "the", firstoccurrence;

Column 5, line 2l, for "an" read and column 6, line 32, for "reelased"read released column 7, line 4l, for "resonate" read resonates column 8,line 51, for "cosntran" read constrain column 13, line 2, for "red" readreed column l5, line 6, for "an dmeans" read and means (SEAL) Signed andsealed this 22nd day of July 1969 Attest:

WILLIAM E. SCHUYLER, JR.

Commissioner of Patents Edward M. Fletcher, J r.

Attesting Officer

1. AN IMBALANCE-OF-ROTATION ARRESTING MEANS FOR USE WITH AN INDUSTRIALCENTRIFUGE EQUIPPED WITH A ROTATABLY MOUNTED CENTRIFUGE BASKET, ANELECTRICAL DRIVE MOTOR ASSOCIATED WITH SAID CENTRIFUGE FOR DRIVING SAIDCENTRIFUGE BASKET, AND A BRAKE FOR RETARDING THE ROTATIONAL MOVEMENT OFTHE CENTRIFUGE BASKET; SAID IMBALANCE-OF-ROTATION ARRESTING MEANSCOMPRISING A RESONANT REED DEVICE OPERATIVELY ASSOCIATED WITH SAIDCENTRIFUGE AND BEING RESONANTRESPONSIVE TO CENTRIFUGE BASKETIMBALANCE-OF-ROTATION FREQUENCY OF VIBRATION, SAID RESONANT REED DEVICEBEING SUBSTANTIALLY COAXIALLY ALIGNED WITH THE CENTER OF ROTATION OFSAID CENTRIFUGE BASKET, MEANS OPERATIVELY ASSOCIATED WITH SAID RESONANTREED DEVICE AND SAID ELECTRICAL DRIVE MOTOR FOR DE-ENERGIZING SAIDELECTRICAL DRIVE MOTOR, SAID LAST NAMED MEANS BEING ACTUATED WHEN SAIDRESONANT REED DEVICE RESONANTES RESPONSIVE TO SAID CENTRIFUGE BASKETIMBALANCE-OF-ROTATION FREQUENCY OF VIBRATION, MEANS OPERATIVELYASSOCIATED WITH SAID RESONANT REED DEVICE AND SAID BRAKE FOR ACTUATINGSAID CENTRIFUGE BASKET BRAKE